1. Field of the Invention
The present invention relates to a navigation system, a route search method, and a storage medium.
2. Description of the Related Art
A navigation system equipped with a map display function includes a route search function to search for a route of the shortest distance from a present position to a destination or a route of the shortest time considering dynamic traffic information. There exists a plurality of conventional methods for setting the destination that is initially set in a route search.
The first conventional method is a method in which a user operates a map displayed on a display to directly specify the position of a destination on the map. This method is effective when the user understands the local geography around the destination to an extent. However, if the user is not familiar with the local geography around the destination, he/she needs to zoom in, zoom out, and scroll the map frequently to search for the specific position of the destination, and the method has a drawback that much time is spent in destination setting.
The second conventional method is a method of directly setting a destination, where the position of a destination is determined, for example, from a telephone number associated with the destination (hereinafter, this method will be called a telephone number input method).
In the telephone number input method, the user enters a telephone number through an input means such as a touch panel provided on the navigation system. A storage device such as a CD-ROM or a DVD-ROM provided in the navigation system stores telephone numbers, positional information where the telephone numbers exist, name information, facility information, address information, message, image and the like which are attribute information of telephone numbers (hereinafter, such information will be called guidance information), and the relationship between area codes/local office numbers and representative positional information of an area covered by the office numbers.
Next, the guidance information is searched based on the telephone number that the user enters. Herein, when a telephone number that matches the telephone number entered by the user is stored as the guidance information, the position of a destination is determined by reading out the positional information in the guidance information.
On the other hand, if a telephone number that matches the telephone number that the user entered is not stored, the representative positional information of an area covered by the area code/local office number associated with the telephone number is searched. Further, a map of the area around the representative position is displayed on a screen, and the user scrolls the map to determine the position of the destination.
By using such a telephone number input method, the destination can be directly set only if the telephone number of the destination is available. Further, there exists a system disclosed in Japanese Patent Publication No. 7-60479 as such a navigation system.
However, since the navigation system disclosed in Japanese Patent Publication No. 7-60479 is designed such that a point represented by office numbers (area code+local office number) is displayed as a way of dealing with the case where the entered telephone number is not contained in the storage medium, a point near the point of the entered telephone number is not necessarily displayed. Thus, there existed a problem that the user needed to scroll a map from the displayed point by operating a remote controller to search for a point that appeared to be a desired destination, and longer time was taken to set the destination.